code: def naive_downsample_2d(x, factor=2):
      _N, C, H, W = x.shape
      x = torch.reshape(
          x, (-1, C, H // factor, factor, W // factor, factor)
      )
      return torch.mean(x, dim=(3, 5))
  
file_path: espnet/espnet2/enh/layers/ncsnpp_utils/up_or_down_sampling.py
imports: import numpy
  import torch
  import torch.nn
  import torch.nn.functional
  from espnet2.enh.layers.ncsnpp_utils.upfirdn2d import upfirdn2d
label_desc: Use image node_id 3 for calling a global function with example usage: naive_downsample_2d(x, factor) and returns: torch